1. Field of the Invention (Technical Field)
The presently claimed invention relates to therapy apparatuses, and more particularly, to a linear motion therapy device for enabling full range of motion for knee or hip problems. A mechanized linear motion therapy device (LMTD) is used after surgery for gentle knee or hip flexion and can be used on an inpatient or an outpatient basis.
2. Background Art
There are several devices in the marketplace for providing physical therapy to a patient after knee or hip surgery; however, most of these devices are for use right after surgery.
Some of these include:
Continuous passive motion (CPM) devices are used during the first phase of rehabilitation following a soft tissue surgical procedure or trauma. CPM is carried out by a CPM device, which constantly moves the joint through a controlled range of motion and provides passive motion in a specific plane of movement. The shortcomings of CPM machines are that they are used only immediately after surgery and up to four weeks afterwards; the device is heavy and difficult for some people to handle when sitting on a surface, it tilts to one side or another, and it is difficult to fit properly for a person with less than a twenty five inch (25″) leg length. Therapeutically, it only approximates calibration of the flexion of the knee, tends to move away from the person using it, thus, not targeting the knee joint which needs to be bent. The CPM spends little time at the height of the knee flexion or at extension because of its continuous motion action and does not completely extend the leg to put femur and tibia into traction for some patients.
Manual therapy is currently being used which includes heel slides whereby the patient lies with his or her back while on a table, bed, or floor with a strap or fastener under the foot and slides the heel closer to the buttocks while holding the strap. When the patient can no longer bend the knee on his/her own, he/she pulls on the ends of the strap to flex the knee further. A physical therapist assistant (PTA) or physical therapist (PT) can also push on the leg to get the maximum flexion. The PTA or PT may then measure the amount of flex with a goniometer. Another in-house therapy method includes use of a heel prop whereby the patient lies on his or her back while on a table, bed, or floor with the postoperative leg fully extended. The heel of this leg is placed on an item such as a rolled up towel, a half-round plastic roll, or other object that keeps the knee fully extended and clears the girth of the calf. At home, the patient may not do the exercises as prescribed; may do them improperly, or not at all. Further, it requires the time of a PT or PTA to teach and then observe to make sure that the patient does the therapies properly.
NK™ tables are also used for therapy. A patient sits on the NK™ table and the postoperative knee/hip is strapped down at the thigh. The knee is then bent to a degree that the patient can tolerate. A long bar with a perpendicular bar to hold weights is attached at the end. Weights are added as needed for resistance to keep the bend. The entire long bar can be adjusted according to the type of bend required. Set up time takes a very long time and cannot be used in a home setting. It does not keep the hip from hiking (moving up) nor does it keep the patient from leaning side to side, thus, keeping the knee from flexing properly or in correct alignment. This device takes time for a PT or PTA or technician to get the patient set up, adjust the device, place the proper weights on the machine, and it cannot be used at the patient's home.
The prior art devices fail to allow a patient to get a true bend and precisely measure the bend. The measurement of bend provides positive reinforcement and motivation to a patient. The presently claimed invention provides a positive environmental setting whether at a therapy location or at home. It is also important because the patient has a very short window of time to improve the bend and break through scar tissue. The thoracic lumbar spine orthosis (TLSO)/back support and thigh support in the presently claimed invention, keep the patient in the correct position unlike manual therapy or slides, which allow too much side to side movement and can also move away from the bend. These aforementioned prior art therapies are inconsistent. Without daily practice, the patient may not improve and once or twice a day is not enough to continue improvement. The claimed invention is for use four weeks after surgery, and is not continuously, but manually controlled by the patient using the device. Further, the claimed invention is adaptable to each patient, and is relatively light (20 pounds) which makes the apparatus easy to handle.